Why are trains yellow at front and back?

[whole diary]

[gpn01]

Apologies if this is posted in the wrong section / forum but it was asked by my six year old who is really enjoying looking at, and travelling on, trains. He then asked a supplementary question.....why is it only overground trains that are painted that way, and yet underground ones aren't? Never fails to amaze me how young children spot things like this as I'd never noticed it.

[Chris from Nailsea]

No problem at all in your posting such a question here, gpn01 - indeed, I can't see where else on the Coffee Shop forum it could have been posed! 

Having posted that - I have absolutely no idea as to the answer, but I'm sure our members will be able to provide us with more information. 

[SandTEngineer]

The answer can be found in section B4 of this document: http://www.rgsonline.co.uk/Railway_Group_Standards/Rolling%20Stock/Railway%20Group%20Standards/GMRT2483%20Iss%201.pdf

Railway Group Standards do not apply to LU or other Metros/Tram Lines so they have their own rules.

[gpn01]

The answer can be found in section B4 of this document: http://www.rgsonline.co.uk/Railway_Group_Standards/Rolling%20Stock/Railway%20Group%20Standards/GMRT2483%20Iss%201.pdf

Railway Group Standards do not apply to LU or other Metros/Tram Lines so they have their own rules.

Brilliant! Where else can you get such a clear answer, to an odd question, but on this forum :-)

Many thanks
Gary

[ChrisB]

low-level tubes travel in their own tunnel & generally can't be seen by oncoming trains - but that doesn't explain it totally as the sub-surface lines do run side-by-side....

[Tim]

I assume that the yellow fronts are the reasons that the trackside workers wear hivis orange as opposed to hivis yellow which is a more common hivis colour away from the railway.

[Red Squirrel]

The answer can be found in section B4 of this document: http://www.rgsonline.co.uk/Railway_Group_Standards/Rolling%20Stock/Railway%20Group%20Standards/GMRT2483%20Iss%201.pdf

Railway Group Standards do not apply to LU or other Metros/Tram Lines so they have their own rules.

Brilliant! Where else can you get such a clear answer, to an odd question, but on this forum :-)

Many thanks
Gary

It does seem odd that TfL^» (Transport for London - about) trains don't have to meet the same standards (you'd think people could agree as to what's safe), but then there are other anomolies:

Why do main-line steam locos require nothing better than "a lit portable head-lamp"  (which implies that an old oil lamp will suffice)?

Why not insist that the last carriage of heritage stock carry a yellow panel (after all the risk of breakdown is, with the best will in the world, higher with old kit)?

[grahame]

As there's a time element to how long ahead a train must be visible in the standards, it follows that higher speed trains need to be visible at a greater distance ... so heritage railways train (25 m.p.h) don't need to be seen so far / be so bright, nor do undergrounds (60 m.p.h).  Main line steam at 75 m.p.h needs to be more visible, and then all the overground / National Rail stuff much of which runs at higher speed.

One of the reasons for the visibiity must be for unguarded foot crossings, of which there remain significant numbers on the National Rai network.  I don't know of any of these on the underground - but at most a handful.

Final note - some pictures of what steam trains would look like if the visibilty extended to main line steam:

http://www.fictitiousliveries.co.uk/photo.php?S4566_fGW.jpg

http://www.fictitiousliveries.co.uk/photo.php?S_WC_SWT.jpg

[Tim]

Why not insist that the last carriage of heritage stock carry a yellow panel (after all the risk of breakdown is, with the best will in the world, higher with old kit)?

because the yellow panels are not there to stop trains hitting each other.  The signalling system is there to do that.   The yellow panels are to make the train more visible to crossing users, trackside worker and anyone else legally or illegally on the track.  Those people are in danger from a train coming towards them.  The risk from the last carriage of a train heading away from them must be lower. 

The answer to the original question "Why are trains yellow at front and back?" is that they are not.  They are only yellow on the front.  But an HST^▸ (High Speed Train) or MU^▸ (Multiple Unit) or a loco have in effect two (potential) fronts because they can change direction.

[paul7575]

A discussion a few years back suggested that from a quite early stage, the forerunners of LU decided that they would not routinely work on the tracks when trains were running,  and wouldn't need the high visibility requirements achieved with a yellow panel.  

(Note the requirement is only for a specific area of about 1 sq m in the group standard - most of the excess area of yellow paint on typical EMUs^▸ (Electric Multiple Unit) etc is applied solely for the purposes of the livery designer.)

The odd overlaps of LU and NR^» (Network Rail - home page) operations are generally subject to special working instructions, and are relatively low speed anyway; but AIUI^▸ (as I understand it) the LU rolling stock still has a formal letter of dispensation against group standards for those areas.

However, there has been an RSSB^▸ (Rail Safety and Standards Board) consultation last December/January on proposals to remove the requirement for a yellow panel as long as the latest high intensity running lights are fitted:  http://consultation.rssb.co.uk/consultation/ConsultationDetail.aspx?ConsultationPackID=481

Don't know what the decision was, but the idea is to remove the requirement from Dec 2015 if agreed.

Paul

[Tim]

I didn't know that.  very interesting.

It strikes me as foolish to remove the yellow end standard even if headlights are now better simply because there is no extra cost in painting them yellow as opposed to any other colour.  I'm all for removing a safety requirement where the need for it has diminished if it imposes a cost on the railway or society at large in money, time or hassle, but I don't see that the requirement for yellow ends does that.   

[Red Squirrel]

Why not insist that the last carriage of heritage stock carry a yellow panel (after all the risk of breakdown is, with the best will in the world, higher with old kit)?

because the yellow panels are not there to stop trains hitting each other.  The signalling system is there to do that.   The yellow panels are to make the train more visible to crossing users, trackside worker and anyone else legally or illegally on the track.  Those people are in danger from a train coming towards them.  The risk from the last carriage of a train heading away from them must be lower. 

The answer to the original question "Why are trains yellow at front and back?" is that they are not.  They are only yellow on the front.  But an HST^▸ (High Speed Train) or MU^▸ (Multiple Unit) or a loco have in effect two (potential) fronts because they can change direction.

You'd think so. But:

The standard also mandates the visibility requirements for the rear of a train so that it can be seen in adequate time by the driver of a train or locomotive approaching it from the rear.

However I had misread the standard - as you say, there's no requirement for a yellow panel to the rear; as far as I can tell an old oil lamp will do for that.

[Tim]

The standard also mandates the visibility requirements for the rear of a train so that it can be seen in adequate time by the driver of a train or locomotive approaching it from the rear.

A red lamp on the back is the last line of defence.  I imagine in the days of time interval working (and thankfully lower speeds) it was more important.

The red lamp on the last vehicle also serves to confirm that the train is complete and that part of the consist hasn't come uncoupled and is blocking the line.  With track circuits and axle counters the signalling system will "notice" lost vehicles, but as I understand it in areas with absolute block signalling, the (wo)man in the signal box is required to note that the complete train has passed and that is done by looking for the red lamp (for obvious reasons the red lamp should ONLY be on the last vehicle).  Only when that has been done can the "train out of section" code be sent to the other box.  How necessary this check is in the modern era is unclear to me because with continuous brakes if the train splits surely BOTH parts come to a stop and the front part never reaches the signal box?

[eightf48544]

Some observations. Yellow ends don't forget the Wasp stripes on 08's and other shunters. I suppose they make them more visable buzzing about a yard.

RE^▸ (Religious Education) tail lamps:
Barnsley has or had a tail light camara from the Wakefield direction which is AB.
Worksop has or had 2 at junctions with AB areas where this point is several miles from the box and it is quite possible for the train not to pass Worksop Box. One is Woodend Jn (Sheffield and Worksop) on the Robinhood line and the other Dinnington Jn on that joint line (most constituent companies?) from Doncaster to the GC^» (Great Central Railway - link to heritage line) at Brancliffe Jn, from which a train can go either to Worksop or Mansfield.

Re headlights. Can someone explain why we don't just have three equal intensity white lights in a triangle as most of Europe does. It seem to me 3 white lights in triangle coming towards you at 125mph is not going to be mistaken for a car!

I have been told the reason the driver has swap the bighter light to the other side at night (can't remember which is which) is so they don't dazzle track workers. When I used to commute at around 07:30 in the morning depending on season and sunrise one train would have left bright the next right bright.

[Bmblbzzz]

I was going to point out the same as eightf48544 - that the requirement for yellow fronts seems to be a British thing. As it's already specific to one rail network, it's not a big surprise it isn't required on LU. Incidentally, I think the triangle of headlights is also used on trams in some countries.